Imaging device and electronic device

ABSTRACT

There is provided an imaging device capable of further improving image quality of a subject, particularly a lesion portion such as cancer. There is provided an imaging device including: a first substrate including a first pixel array unit in which a plurality of pixels having at least a first photoelectric conversion unit is arranged in a two-dimensional manner, a first wiring layer, and a first support layer stacked in this order; and a second substrate including a second pixel array unit in which a plurality of pixels having at least a second photoelectric conversion unit is arranged in a two-dimensional manner, a second wiring layer, and a second support layer stacked in this order, in which the first support layer and the second support layer are bonded to each other to form a stacked structure, and at least one of the support layers includes an antireflection layer.

TECHNICAL FIELD

The present technology relates to an imaging device and an electronicdevice.

BACKGROUND ART

In recent years, as the demand for imaging devices (image sensors) hasbeen increasing, endoscopic systems equipped with imaging devices (imagesensors) have been widely used to detect cancer in living tissue or thelike.

For example, Patent Document 1 proposes a technology capable ofsimultaneously acquiring a visible light image and an infrared lightimage with an inexpensive configuration.

CITATION LIST Patent Document

-   Patent Document 1: Japanese Patent Application Laid-Open No.    2014-135535

SUMMARY OF THE INVENTION Problems to be Solved by the Invention

However, the technology proposed in Patent Document 1 may not be capableof further improving image quality of a subject, particularly a lesionportion such as cancer.

Accordingly, the present technology has been made in view of such asituation, and has a main object to provide an imaging device that canachieve further improvement of the image quality of a subject,particularly a lesion portion such as cancer, and an electronic deviceequipped with the imaging device.

Solutions to Problems

As a result of diligent research to achieve the above-described object,the present inventors have succeeded in achieving further improvement ofthe image quality of an imaging device, and have completed the presenttechnology.

That is, in the present technology, there is provided an imaging deviceincluding:

a first substrate including a first pixel array unit in which aplurality of pixels having at least a first photoelectric conversionunit that performs photoelectric conversion is arranged in atwo-dimensional manner, a first wiring layer, and a first support layerstacked in this order, and

a second substrate including a second pixel array unit in which aplurality of pixels having at least a second photoelectric conversionunit that performs photoelectric conversion is arranged in atwo-dimensional manner, a second wiring layer, and a second supportlayer stacked in this order,

in which the first support layer and the second support layer are bondedto each other to form a stacked structure of the first substrate and thesecond substrate, and

at least one of the first support layer or the second support layerincludes an antireflection layer.

As a first aspect of the imaging device according to the presenttechnology,

the antireflection layer may include a light-shielding film that shieldsexcitation light with which a subject is irradiated and/or atransmission film that transmits fluorescence emitted from the subjectby the excitation light, and in this case, the excitation light may havea wavelength of 760 nm±10 nm, and the fluorescence may have a wavelengthof 850 nm±10 nm.

As a second aspect of the imaging device according to the presenttechnology,

the first support layer may include a first antireflection layer, andthe second support layer may include a second antireflection layer, thefirst antireflection layer may include a light-shielding film thatshields excitation light with which a subject is irradiated and/or atransmission film that transmits fluorescence emitted from the subjectby the excitation light, and

the second antireflection layer may include a light-shielding film thatshields excitation light with which a subject is irradiated and/or atransmission film that transmits fluorescence emitted from the subjectby the excitation light, and in this case, the excitation light may havea wavelength of 760 nm±10 nm, and the fluorescence may have a wavelengthof 850 nm±10 nm.

As a third aspect of the imaging device according to the presenttechnology,

the first support layer may include a first adhesive layer, a firstantireflection layer, and a second adhesive layer stacked in this order,

the second support layer may include a third adhesive layer, a secondantireflection layer, and a fourth adhesive layer stacked in this order,

the second adhesive layer and the third adhesive layer may be bonded toeach other to form a stacked structure of the first substrate and thesecond substrate,

the first antireflection layer may include a light-shielding film thatshields excitation light with which a subject is irradiated and/or atransmission film that transmits fluorescence emitted from the subjectby the excitation light, and

the second antireflection layer may include a light-shielding film thatshields excitation light with which a subject is irradiated and/or atransmission film that transmits fluorescence emitted from the subjectby the excitation light, and in this case, the excitation light may havea wavelength of 760 nm±10 nm, and the fluorescence may have a wavelengthof 850 nm±10 nm.

In the third aspect of the imaging device according to the presenttechnology,

the first adhesive layer may include a silicon oxide film, the firstantireflection layer may include a silicon nitride film, and the secondadhesive layer may include a silicon oxide film, and

the third adhesive layer may include a silicon nitride film, the secondantireflection layer may include a silicon oxide film, and the fourthadhesive layer may include a silicon nitride film.

In the third aspect of the imaging device according to the presenttechnology,

the first adhesive layer may include a silicon nitride film, the firstantireflection layer may include a silicon oxide film, and the secondadhesive layer may include a silicon nitride film, and

the third adhesive layer may include a silicon oxide film, the secondantireflection layer may include a silicon nitride film, and the fourthadhesive layer may include a silicon oxide film.

As a fourth aspect of the imaging device according to the presenttechnology,

a light emitting element that outputs excitation light with which asubject is irradiated may be further included.

As a fifth aspect of the imaging device according to the presenttechnology,

the second wiring layer may have a wiring, and the wiring may be atransparent wiring.

As a sixth aspect of the imaging device according to the presenttechnology,

the second wiring layer may have a wiring, and the wiring may bearranged in at least one area corresponding to between the pixelsadjacent to each other in the plurality of pixels arrangedtwo-dimensionally in the second pixel array unit.

As a seventh aspect of the imaging device according to the presenttechnology,

the second wiring layer may have a wiring, and the wiring may bearranged only in an area corresponding to the pixels of at least a partof the plurality of pixels arranged two-dimensionally in the secondpixel array unit.

Moreover, the present technology provides an electronic device equippedwith an imaging device according to the present technology.

According to the present technology, further improvement in imagequality can be achieved. Note that the effects described here are notnecessarily limited, and may be any effect described in the presentdisclosure.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a cross-sectional view illustrating a configuration example ofan imaging device to which the present technology is applied.

FIG. 2 is a cross-sectional view illustrating a configuration example ofthe imaging device to which the present technology is applied.

FIG. 3 is a view for explaining a relationship between a wiring andpixels (photodiodes (PD)).

FIG. 4 is a view for explaining a relationship between a wiring andpixels (photodiodes (PD)).

FIG. 5 is a view for explaining a relationship between a wiring andpixels (photodiodes (PD)).

FIG. 6 is a cross-sectional view for explaining a manufacturing methodof the imaging device to which the present technology is applied.

FIG. 7 is a diagram for explaining the relationship between reflectanceand wavelength.

FIG. 8 is a cross-sectional view illustrating a configuration example ofthe imaging device to which the present technology is applied.

FIG. 9 is a diagram illustrating a configuration example of a camerasystem using the imaging device to which the present technology isapplied.

FIG. 10 is a cross-sectional view illustrating a general configurationexample of the imaging device.

FIG. 11 is a block diagram illustrating a configuration example of aninternal information acquisition system including a capsule-typeendoscope using the imaging device to which the present technology isapplied.

FIG. 12 is a diagram illustrating an example of using an imaging deviceto which the present technology is applied.

FIG. 13 is a diagram illustrating an example of a schematicconfiguration of an endoscopic surgery system.

FIG. 14 is a block diagram illustrating an example of a functionalconfiguration of a camera head and a CCU.

MODE FOR CARRYING OUT THE INVENTION

Hereinafter, preferred embodiments for carrying out the presenttechnology will be described. Note that the embodiments described beloware examples of representative embodiments of the present technology,and the scope of the present technology is not interpreted in a narrowsense by them. Note that unless otherwise specified, in the drawings,“upper” means an upper direction or an upper side in the drawings,“lower” means a lower direction or a lower side in the drawings, “left”means a left direction or a left side in the drawings, and “right” meansa right direction or a right side in the drawings. Furthermore, in thedrawings, the same or equivalent elements or members are designated bythe same reference numerals, and duplicate descriptions will be omitted.

The description will be made in the following order.

1. Overview of present technology

2. First embodiment (example 1 of imaging device)

3. Second embodiment (example 2 of imaging device)

4. Third embodiment (example of electronic device)

5. Application example of imaging device to which present technology isapplied

-   -   5-1. Configuration example of camera system    -   5-2. Example of application to internal information acquisition        system including capsule-type endoscope    -   5-3. Example of using imaging device    -   5-4. Example of application to endoscopic surgery system

1. Overview of Present Technology

First, the overview of the present technology will be described.

In the case of an endoscopic system, in addition to normal observationusing visible light, special observation using infrared light or thelike is performed. A fluorescent substance called indocyanine green(ICG), which has an affinity for lesions such as cancer and is excitedto fluoresce in the infrared region, is administered into the body of atest subject in advance and irradiated with excitation light thatexcites the fluorescent substance, and thereby the fluorescence from thefluorescent substance accumulated in the lesion portion can be detected.Since strong fluorescence is emitted from the lesion portion, presenceor absence of a lesion can be determined from brightness of thefluorescence image.

Examples of medical fluorescent substances (fluorescent materials)include Katushka2S (excitation wavelength 588 nm, fluorescencewavelength 633 nm), above-described ICG (excitation wavelength 750 to810 nm, fluorescence wavelength 835 nm), and 5-ALA (excitationwavelength 375 to 445 nm, Fluorescence wavelength 600 to 740 nm).

FIG. 10 illustrates an imaging device 500. It is a cross-sectional viewillustrating a cross section of an imaging device having a support layer4010 sandwiched between a first substrate 1010 and a second substrate1020. The imaging device 400 includes a first substrate 1010, a secondsubstrate 1020, a color filter 1030, a connection portion 1040, and asupport layer 4010.

The imaging device 500 detects not only a desired fluorescence Q1 (forexample, wavelength 850 nm) but also a reflected light P2 (for example,wavelength 760 nm) of an excitation light P1 (for example, wavelength760 nm) from a subject (for example, ICG sample) R, and has an SN ratiothat is not preferable in some cases. In a case where a light-shieldingfilm is set on an upper layer (for example, the color filter 1030) ofthe imaging device 500, light other than the excitation light P1 is alsoshielded, and thus an optical design may be difficult.

The present technology has been made in view of the above. The presenttechnology is an imaging device including a first substrate including afirst pixel array unit in which a plurality of pixels having at least afirst photoelectric conversion unit that performs photoelectricconversion is arranged in a two-dimensional manner, a first wiringlayer, and a first support layer stacked in this order, and a secondsubstrate including a second pixel array unit in which a plurality ofpixels having at least a second photoelectric conversion unit thatperforms photoelectric conversion is arranged in a two-dimensionalmanner, a second wiring layer, and a second support layer stacked inthis order, in which the first support layer and the second supportlayer are bonded to each other to form a stacked structure of the firstsubstrate and the second substrate, and at least one of the firstsupport layer or the second support layer includes an antireflectionlayer. The antireflection layer may be formed by one film or a pluralityof films. Then, the antireflection layer can include a light-shieldingfilm that shields excitation light and/or a transmission film thattransmits fluorescence emitted from the subject by the excitation light.

According to the present technology, further improvement in imagequality of a subject, particularly a lesion portion such as cancer, canbe achieved. Specifically, according to the present technology, theexcitation light can be selectively shielded, the fluorescence can beselectively transmitted, or the excitation light can be selectivelyshielded and the fluorescence can be selectively transmitted.

Hereinafter, imaging devices of embodiments (first embodiment and secondembodiment) according to the present technology will be describedconcretely and in detail.

2. First Embodiment (Example 1 of Imaging Device)

An imaging device of a first embodiment (Example 1 of the imagingdevice) according to the present technology includes a first substrateincluding a first pixel array unit in which a plurality of pixels havingat least a first photoelectric conversion unit that performsphotoelectric conversion is arranged in a two-dimensional manner, afirst wiring layer, and a first support layer stacked in this order, anda second substrate including a second pixel array unit in which aplurality of pixels having at least a second photoelectric conversionunit that performs photoelectric conversion is arranged in atwo-dimensional manner, a second wiring layer, and a second supportlayer stacked in this order, in which the first support layer and thesecond support layer are bonded to each other to form a stackedstructure of the first substrate and the second substrate, and at leastone of the first support layer or the second support layer includes anantireflection layer.

With the imaging device of the first embodiment (Example 1 of theimaging device) according to the present technology, further improvementin image quality of a subject, particularly a lesion portion such ascancer, can be achieved. Specifically, with the imaging device of thefirst embodiment (Example 1 of the imaging device) according to thepresent technology, an optical design capable of shielding excitationlight and transmitting fluorescence can be achieved.

Hereinafter, the imaging device of the first embodiment according to thepresent technology will be described using FIGS. 1 to 7.

First, the description will be given using FIG. 1. FIG. 1 is across-sectional view illustrating an imaging device 1-1 of the firstembodiment according to the present technology.

The imaging device 1-1 illustrated in FIG. 1 includes a first substrate101 and a second substrate 102, in which the first substrate 101 and thesecond substrate 102 are bonded to each other via a connection portion104 arranged on left side surfaces of the first substrate 101 and thesecond substrate 102, so as to have a stacked structure of the firstsubstrate 101 and the second substrate 102. More specifically, theimaging device 1-1 includes a first substrate including a first pixelarray unit 101C having a color filter 13, a first wiring layer 101B, anda first support layer 101A stacked in this order, and a second substrate102 including a second pixel array unit 102C, a second wiring layer102B, and a second support layer 102A stacked in this order, in whichthe first support layer 101A and the second support layer 101B arebonded to each other to form a stacked structure of the first substrate101 and the second substrate 102.

Furthermore, it may be considered that in the imaging device 1-1, withthe first pixel array unit 101C and the first wiring layer 101B of thefirst substrate 101 and the second pixel array unit 102C and the secondwiring layer 102B of the second substrate 102, the first wiring layer101B and the second wiring layer 102B are bonded to each other with thefirst support layer 101A of the first substrate 101 and the secondsupport layer 102A of the second substrate 102 interposed therebetween,forming a stacked structure of the first pixel array unit 101C and thefirst wiring layer 101B, and the second pixel array unit 102C and thesecond wiring layer 102B.

The first support layer 101A includes a first adhesive layer 31A and afirst antireflection layer 41 stacked, the second support layer 102Aincludes a fourth adhesive layer 32A and a second antireflection layer42 stacked, and a first antireflection layer 41 and a secondantireflection layer 42 are bonded to each other via a joint surfaceS-1. The joint surface S-1 is formed by a lower surface (lower side ofFIG. 1) of the first antireflection layer 41 and an upper surface (upperside of FIG. 1) of the second antireflection layer 42.

Although not illustrated in FIG. 1, the first support layer 101A may beprovided with a second adhesive layer on a surface of the firstantireflection layer 41 on which the first adhesive layer 31A is notstacked (in FIG. 1, the lower surface of the first antireflection layer41), the first support layer 102A may be provided with a third adhesivelayer on a surface of the second antireflection layer 42 on which thefourth adhesive layer 32A is not stacked (in FIG. 1, the upper surfaceof the second antireflection layer 42), and in this case, the jointsurface S-1 is formed by a lower surface (lower side of FIG. 1) of thesecond adhesive layer and an upper surface (upper side of FIG. 1) of thethird adhesive layer.

In the imaging device 1-1 in FIG. 1, the first adhesive layer 31A andthe fourth adhesive layer 32A are directly bonded to each other whilebeing in contact with the connection portion 104, and a part of the leftside of the joint surface S-1 (left side in FIG. 1) is formed by a lowersurface of the first adhesive layer 31A and an upper surface of thefourth adhesive layer 32A. Note that without having a part where thefirst adhesive layer 31A and the fourth adhesive layer 32A are directlybonded to each other, the entire joint surface S-1 (entire surface) maybe formed by the lower surface (lower side of FIG. 1) of the firstantireflection layer 41 and the upper surface (upper side of FIG. 1) ofthe second antireflection layer 42 or, as described above, although notillustrated in FIG. 1, may be formed by the lower surface (lower side ofFIG. 1) of the second adhesive layer and the upper surface (upper sideof FIG. 1) of the third adhesive layer.

In the imaging device 1-1, fluorescence Q1 (for example, a wavelength of850 nm) is selectively transmitted through the first support layer 101Aand the second support layer 102A and is detected by the second pixelarray unit 102C (second substrate 102). The reflected light P2 (forexample, wavelength 760 nm) of the excitation light P1 (for example,wavelength 760 nm) from the subject (for example, ICG sample) R isshielded in the first support layer 101A and/or in the second supportlayer 102A.

Next, the description will be given using FIG. 2. FIG. 2(a) is across-sectional view illustrating an imaging device 1-2 of the firstembodiment according to the present technology, and FIG. 2(b) is anenlarged cross-sectional view of the first substrate 101 provided in theimaging device 1-2 excluding the first support layer 101A, that is, thefirst pixel array unit 101C and the first wiring layer 101B and anenlarged cross-sectional view of the first substrate 102 provided in theimaging device 1-2 excluding the second support layer 102A, that is, thesecond pixel array unit 102C and the second wiring layer 102B.

As illustrated in FIG. 2(a), the imaging device 1-2 of the firstembodiment according to the present technology includes the firstsubstrate 101 and the second substrate 102, and the first substrate 101and the second substrate 102 are bonded to each other via the connectionportion 104 arranged on the left side surfaces of the first substrate101 and the second substrate 102 to have a stacked structure of thefirst substrate 101 and the second substrate 102. That is, the imagingdevice 1-2 includes a first substrate including a first pixel array unit101C having a color filter 13, a first wiring layer 101B, and a firstsupport layer 101A stacked in this order, and a second substrate 102including a second pixel array unit 102C, a second wiring layer 102B,and a second support layer 102A stacked in this order, in which thefirst support layer 101A and the second support layer 101B are bonded toeach other to form a stacked structure of the first substrate 101 andthe second substrate 102.

Furthermore, it may be considered that in the imaging device 1-2, withthe first pixel array unit 101C and the first wiring layer 101B of thefirst substrate 101 and the second pixel array unit 102C and the secondwiring layer 102B of the second substrate 102, the first wiring layer101B and the second wiring layer 102B are bonded to each other with thefirst support layer 101A of the first substrate 101 and the secondsupport layer 102A of the second substrate 102 interposed therebetween,forming a stacked structure of the first pixel array unit 101C and thefirst wiring layer 101B, and the second pixel array unit 102C and thesecond wiring layer 102B.

The first support layer 101A includes a first adhesive layer 31A and afirst antireflection layer 41 stacked, the second support layer 102Aincludes a fourth adhesive layer 32A and a second antireflection layer42 stacked, and a first antireflection layer 41 and a secondantireflection layer 42 are bonded to each other via a joint surfaceS-1. The joint surface S-1 is formed by a lower surface (lower side ofFIG. 2(a)) of the first antireflection layer 41 and an upper surface(upper side of FIG. 2(a)) of the second antireflection layer 42.

Although not illustrated in FIG. 2(a), the first support layer 101A maybe provided with a second adhesive layer on a surface of the firstantireflection layer 41 on which the first adhesive layer 31A is notstacked (in FIG. 2(a), the lower surface of the first antireflectionlayer 41), the first support layer 102A may be provided with a thirdadhesive layer on a surface of the second antireflection layer 42 onwhich the fourth adhesive layer 32A is not stacked (in FIG. 2(a), theupper surface of the second antireflection layer 42), and in this case,the joint surface S-1 is formed by a lower surface (lower side of FIG.2(a)) of the second adhesive layer and an upper surface (upper side ofFIG. 2(a)) of the third adhesive layer.

In the imaging device 1-2 in FIG. 2(a), the first adhesive layer 31A andthe fourth adhesive layer 32A are directly bonded to each other whilebeing in contact with the connection portion 104, and a part of the leftside of the joint surface S-1 (left side in FIG. 1) is formed by a lowersurface of the first adhesive layer 31A and an upper surface of thefourth adhesive layer 32A. Note that without having a part where thefirst adhesive layer 31A and the fourth adhesive layer 32A are directlybonded to each other, the entire joint surface S-1 (entire surface) maybe formed by the lower surface (lower side of FIG. 1) of the firstantireflection layer 41 and the upper surface (upper side of FIG. 1) ofthe second antireflection layer 42 or, as described above, although notillustrated in FIG. 2(a), may be formed by the lower surface (lower sideof FIG. 2(a)) of the second adhesive layer and the upper surface (upperside of FIG. 2(a)) of the third adhesive layer.

FIG. 2(b) illustrates a stacked structure of the first pixel array unit101C and the first wiring layer 101B and a stacked structure of thesecond pixel array unit 102C and the second wiring layer 102B, as anenlarged cross-sectional view.

In the first pixel array unit 101C, an on-chip lens 12, a color filter13, and a first photoelectric conversion unit (for example, photodiode(PD)) 50-1 that performs photoelectric conversion of visible light areformed in order from an incident side of light (upper side in FIG.2(b)), and a first wiring 51-1 and the like are formed in the firstwiring layer 101B below the first pixel array unit 101C (lower side inFIG. 2(b)). Then, a second photoelectric conversion unit (for example,photodiode (PD)) 50-2 that performs photoelectric conversion offluorescence is formed on an upper portion (upper side in FIG. 2(b)) ofthe second pixel array unit 102C, and a second wiring 51-2 and the likeare formed in the second wiring layer 102B above the second pixel arrayunit 102C.

As described above, the imaging device 1-2 includes the first pixelarray unit 101C that detects visible light and the second pixel arrayunit 102C that detects fluorescence, and since the first wiring layer101B and the second wiring layer 102B are arranged in order from theincident side of light (upper side in FIG. 2) between the first pixelarray unit 101C and the second pixel array unit 102C, when the firstwiring 51-1 formed in the first wiring layer 101B and/or the secondwiring 51-2 formed in the second wiring layer 102B is a metal wiringsuch as tungsten (W) or aluminum (Al), fluorescence may be shieldedbefore the fluorescence reaches the second pixel array unit 102C.

As long as the second pixel array unit 102C can detect fluorescence, thefirst wiring 51-1 may be a metal wiring such as tungsten (W) or aluminum(Al), and the second wiring 51-2 may be a metal wiring such as tungsten(W) or aluminum (Al). However, in a case where efficient detection offluorescence is performed, the first wiring 51-1 is preferably atransparent wiring (for example, a wiring including ITO), and the secondwiring 51-2 is preferably a transparent wiring (for example, a wiringincluding ITO). Then, in a case where further efficient detection offluorescence is performed, it is preferable that both the first wiring51-1 and the second wiring 51-2 are transparent wirings (for example,wirings including ITO).

Avoidance of shielding fluorescence will be further described usingFIGS. 3 to 5.

FIGS. 3 to 5 are top views for explaining the relationship betweenwiring and pixels (photodiodes (PD)) in the imaging device of the firstembodiment according to the present technology.

First, the description will be given using FIG. 3. In FIG. 3, pixels20-3 a to 20-3 d for four pixels are illustrated, a wiring 21-3 isarranged between the pixels 20-3 a and the pixels 20-3 c adjacent toeach other and between the pixels 20-3 b and the pixels 20-3 d adjacentto each other. That is, by arranging the wiring at the boundary betweenone photoelectric conversion unit (for example, a photodiode) and theother photoelectric conversion unit (for example, a photodiode) adjacentto each other without arranging the wiring 21-3 at a substantiallycenter portion of the photoelectric conversion unit (for example, aphotodiode) that the pixels 20-3 a to 20-3 d for four pixels have forevery pixel, the second pixel array unit 102C can detect fluorescenceefficiently even if the wiring 21-3 is a metal wiring. Note that if thewiring 21-3 is a transparent wiring, the second pixel array unit 102Ccan detect fluorescence more efficiently. The wiring 21-3 may be used asthe first wiring 51-1, may be used as the second wiring 51-2, or may beused for both the first wiring 51-1 and the second wiring 51-2.

Next, the description will be given using FIG. 4. In FIG. 4, pixels 20-4a for 4 pixels, pixels 20-4 b for 4 pixels, pixels 20-4 c for 4 pixels,and pixels 20-4 d for 4 pixels are illustrated (16 pixels in total), anda wiring 21-4 is arranged so as to correspond to the pixels 20-4 b, thepixels 20-4 c, and the pixels 20-d for 12 pixels, and the wiring 21-4 isnot arranged to locations corresponding to the pixels 20-4 a for 4pixels. That is, with the configuration of this wiring arrangement, byseparating into the pixels that detect fluorescence (pixels 20-4 a inFIG. 4) and the pixels that do not detect fluorescence (pixels 20-4 b,pixels 20-4 c, and pixels 20-4 d in FIG. 4)), the second pixel arrayunit 102C can efficiently detect fluorescence even if the wiring 21-4 isa metal wiring. Note that if the wiring 21-4 is a transparent wiring,the second pixel array unit 102C can detect fluorescence moreefficiently. The configuration of the wiring arrangement illustrated inFIG. 4 may be applied to the first wiring layer 101B, the second wiringlayer 102B, or both the first wiring layer 101B and the second wiringlayer 102B.

This will be described using FIG. 5. In FIG. 5, pixels 20-5 a to 20-5 dfor four pixels are illustrated, and a wiring 21-5 is arrangedcorresponding to each pixel of pixels 20-5 a to 20-5 d. In a case wherefluorescence is not shielded by the wiring 21-5, the photoelectricconversion unit (photodiode (PD)) of each pixel of the pixels 20-5 a to20-5 d can detect the fluorescence and thus a metal wiring may be usedfor the wiring 21-5, but in a case where fluorescence is shielded by thewiring 21-5 or is not shielded more efficiently, it is preferable to usetransparent wiring for the wiring 21-5. As long as fluorescence can bedetected, the wiring 21-5 may be used as the first wiring 51-1, may beused as the second wiring 51-2, or may be used for both the first wiring51-1 and the second wiring 51-2.

FIG. 6 is a cross-sectional view for explaining a manufacturing methodof an imaging device 1-6 of the first embodiment according to thepresent technology.

FIGS. 6(a-1) and 6(a-2) illustrate a manufacturing method of the firstsubstrate 101. As illustrated in FIG. 6(a-1), the first wiring layer101B is stacked on the first pixel array unit 101C.

In FIG. 6(a-2), the first support layer 101A is stacked on the firstwiring layer 101B. That is, the first adhesive layer 31A is stacked onthe first wiring layer 101B, the first antireflection layer 41 isstacked on the first adhesive layer 31A, and a second adhesive layer 31Bis stacked on the first antireflection layer 41, thereby manufacturingthe first substrate 101.

FIGS. 6(b-1) and 6(b-2) illustrate a manufacturing method of the secondsubstrate 102. As illustrated in FIG. 6(b-1), the second wiring layer102B is stacked on the second pixel array unit 102C.

In FIG. 6(b-2), the second support layer 102A is stacked on the secondwiring layer 102B. That is, the fourth adhesive layer 32A is stacked onthe second wiring layer 101B, the second antireflection layer 42 isstacked on the fourth adhesive layer 32A, and a third adhesive layer 32Bis stacked on the first antireflection layer 42, thereby manufacturingthe second substrate 102.

As illustrated in FIG. 6(c), the first substrate 101 being rotated 180degrees and the second adhesive layer 31B and the third adhesive layer32B are bonded to each other so that a lower surface (lower side in FIG.8(c)) of the second adhesive layer 31B of the first substrate 101 and anupper surface (upper side in FIG. 8(c)) of the third adhesive layer 32Bof the second substrate 102 are bonded to each other so as to form ajoint surface S-6, thereby manufacturing the imaging device 1-6.

The imaging device 1-6 includes a first substrate including a firstpixel array unit 101C having a photoelectric conversion unit (PD) 50-1,a first wiring layer 101B, and a first support layer 101A stacked inthis order, and a second substrate 102 including a second pixel arrayunit 102C having a photoelectric conversion unit (PD) 50-2, a secondwiring layer 102B, and a second support layer 102A stacked in thisorder, in which the first support layer 101A and the second supportlayer 101B are bonded to each other to form a stacked structure of thefirst substrate 101 and the second substrate 102.

Each of the first adhesive layer 31A, the first antireflection layer 41,and the second adhesive layer 31B may be formed by one film or may beformed by a plurality of films. Each of the fourth adhesive layer 32A,the second antireflection layer 42, and the third adhesive layer 32B maybe formed by one film or may be formed by a plurality of films.

In a case where each of the first adhesive layer 31A, the firstantireflection layer 41, and the second adhesive layer 31B is formed byone film, and each of the fourth adhesive layer 32A, the secondantireflection layer 42, and the third adhesive layer 32B is formed byone film, for example, it is sufficient if the first adhesive layer 31Ais a silicon oxide film (SiO film), the first antireflection layer 41 isa silicon nitride film (SiN film), the second adhesive layer 31B is asilicon oxide film (SiO film), the third adhesive layer 32B is a siliconnitride film (SiN film), the second antireflection layer 42 is a siliconoxide film (SiO film), and the fourth adhesive layer 32A is a siliconnitride film (SiN film).

In a case where each of the first adhesive layer 31A, the firstantireflection layer 41, and the second adhesive layer 31B is formed bya plurality of films, and each of the fourth adhesive layer 32A, thesecond antireflection layer 42, and the third adhesive layer 32B isformed by a plurality of films, for example, it is sufficient if aninterface film of the first adhesive layer 31A in contact with the firstantireflection layer 41 is a silicon oxide film (SiO film), an interfacefilm of the first antireflection layer 41 in contact with the firstadhesive layer 31A is a silicon nitride film (SiN film), and aninterface film of the second adhesive layer 31B in contact with thefirst antireflection layer 41 is a silicon oxide film (SiO film). Then,it is sufficient if an interface film of the third adhesive layer 32B incontact with the second antireflection layer 42 is a silicon nitridefilm (SiN film), an interface film of the second antireflection layer 42in contact with the third adhesive layer 32B is a silicon oxide film(SiO film), and an interface film of the fourth adhesive layer 32A incontact with the second antireflection layer 42 is a silicon nitridefilm (SiN film).

FIG. 7 is a graph of an example for explaining the relationship betweenthe reflectance (vertical axis) and the wavelength (horizontal axis) inthe imaging device of the first embodiment according to the presenttechnology.

As illustrated in FIG. 7, the imaging device 1 (1-1, 1-2, 1-6) of thefirst embodiment according to the present technology has the effect ofselectively shielding excitation light (high reflectance as illustratedin FIG. 7) and selectively transmitting fluorescence (low reflectance asillustrated in FIG. 7) by the antireflection layers 41 and 42. Theantireflection layer 41 includes, for example, a silicon oxide film (SiOfilm) or a silicon nitride film (SiN film), and includes alight-shielding film that shields excitation light and/or a transmissionfilm that transmits fluorescence emitted from the subject by theexcitation light. The antireflection layer 42 includes, for example, asilicon oxide film (SiO film) or a silicon nitride film (SiN film), andincludes a light-shielding film that shields excitation light and/or atransmission film that transmits fluorescence emitted from the subjectby the excitation light. In a case where the subject is an ICG sample,the excitation light has a wavelength of 760 nm±10 nm, and thefluorescence has a wavelength of 850 nm±10 nm.

To the imaging device of the first embodiment according to the presenttechnology, in addition to the contents described above, contents thatwill be described in the section of an imaging device of a secondembodiment according to the present technology, which will be describedlater, can be applied as long as there are no particular technicalcontradictions.

3. Second Embodiment (Example 2 of Imaging Device)

An imaging device of the first embodiment (Example 2 of the imagingdevice) according to the present technology includes a first substrateincluding a first pixel array unit in which a plurality of pixels havingat least a first photoelectric conversion unit that performsphotoelectric conversion is arranged in a two-dimensional manner, afirst wiring layer, and a first support layer stacked in this order, anda second substrate including a second pixel array unit in which aplurality of pixels having at least a second photoelectric conversionunit that performs photoelectric conversion is arranged in atwo-dimensional manner, a second wiring layer, and a second supportlayer stacked in this order, in which the first support layer and thesecond support layer are bonded to each other to form a stackedstructure of the first substrate and the second substrate, and at leastone of the first support layer or the second support layer includes anantireflection layer, and a light emitting element that outputsexcitation light with which a subject (for example, a sample) isirradiated is further included. The light emitting element may be, forexample, an LED element, a laser element, or the like.

With the imaging device of the second embodiment (example 2 of theimaging device) according to the present technology, further improvementin image quality of the subject, particularly a lesion portion such ascancer, can be achieved. Specifically, with the imaging device of thesecond embodiment (example 2 of the imaging device) according to thepresent technology, an optical design capable of shielding excitationlight and transmitting fluorescence can be achieved. Furthermore, sincethe imaging device of the second embodiment (example 2 of the imagingdevice) according to the present technology includes the light emittingelement, it is possible to improve convenience at a time of surgery orthe like.

Hereinafter, the imaging device of the second embodiment according tothe present technology will be described using FIG. 8.

FIG. 8 is a cross-sectional view illustrating the imaging device 1-8 ofthe second embodiment according to the present technology.

The imaging device 1-8 includes a glass (for example, sapphire glass)21, a first pixel array unit 101C having an on-chip lens 12, a colorfilter 13, and a first photoelectric conversion unit (for example,photodiode (PD)), a second pixel array unit 102 having a first wiringlayer 101B, a first support layer 101A, a second support layer 102A, asecond wiring layer 102B, and a second photoelectric conversion unit(for example, photodiode (PD)), and solder balls 47, in order from anincident side (incident light side) of light. Then, the imaging device1-8 further includes a light emitting element (for example, a blue LEDelement) 200 (an n layer 22, a light emitting layer 23, and a p layer24). The light emitting element 200 can output excitation light asirradiation light with which a subject (for example, an ICG sample) isirradiated. For example, fluorescence emitted from the subject (forexample, an ICG sample) by the excitation light is photoelectricallyconverted by the second pixel array unit 102C to generate a pixelsignal, and visible light is separated by the color filter 13 andphotoelectrically converted by the first pixel array unit 101C togenerate a pixel signal.

The imaging device 1-8 can be manufactured by, for example, awafer-level chip size package (WCSP) manufacturing method such that afirst substrate 101 and a second substrate 102 for a plurality of chipsand a substrate on which the light emitting elements 200 for a pluralityof chips are formed (not illustrated in FIG. 8) are bonded together.Then, by using the sapphire glass 21, which has higher strength comparedto ordinary glass (for example, SiO glass), thinning of the cover glassand height reduction (module miniaturization) of the imaging device 1-8as a whole can be achieved.

The on-chip lens 12 focuses incident light (for example, visible light)on the color filter 13. In the color filter 13, for example, respectivecolor filters of R, G, and B are arranged according to a Bayer array.

In the first wiring layer 101B, a first wiring, a signal processingcircuit that processes a pixel signal converted by the first pixel arrayunit 101C, an I/O circuit for taking out an external terminal, and thelike are formed. The signal processing circuit, the I/O circuit, and thelike formed in the first wiring layer 101B are arranged withoutprotruding in a horizontal direction (left-right direction in FIG. 8)from the area occupied by the first pixel array unit 101C on an upperlayer side (upper side in FIG. 8).

Furthermore, in the second wiring layer 102B, a second wiring, a signalprocessing circuit that processes a pixel signal converted by the secondpixel array unit 102C, an I/O circuit for taking out an externalterminal, and the like are formed. The signal processing circuit, I/Ocircuit, and the like formed in the second wiring layer 102B arearranged without protruding in the horizontal direction (left-rightdirection in FIG. 8) from the area occupied by the second pixel arrayunit 102C on a lower layer side (lower side in FIG. 8).

The imaging device 1-8 is connected to the outside via solder balls 47.A voltage is applied to the light emitting element 200 via solder balls44 and silicon vias (through electrodes) 43, and solder balls 46 andvias 45, and the light emitting element 200 outputs irradiation light(excitation light) according to the applied voltage.

To the imaging device of the second embodiment according to the presenttechnology, in addition to the contents described above, the contentsdescribed in the section of the solid-state imaging device of the firstembodiment according to the present technology described above can beapplied as they are as long as there are no particular technicalcontradictions.

4. Third Embodiment (Example of Electronic Device)

An electronic device of a third embodiment according to the presenttechnology is an electronic device equipped with the imaging device ofeither one of the first and second embodiments according to the presenttechnology. Hereinafter, specific examples of the electronic device ofthe third embodiment according to the present technology (applicationexample of the imaging device to which the present technology isapplied) will be described in detail.

5. Application Example of Imaging Device to Which Present Technology isApplied

[5-1. Configuration Example of Camera System]

The imaging devices of the first and second embodiments according to thepresent technology can be applied to a camera system. FIG. 9 is adiagram illustrating a configuration example of a camera system 1000 towhich the imaging device of the first embodiment according to thepresent technology is applied. The camera system 1000 includes afluorescence sensor 1001, a light source 1002, and a camera lens barrel1003. The light source 1002 irradiates a subject (for example, an ICGsample) 1004 with excitation light. The imaging device of the firstembodiment according to the present technology is used as thefluorescence sensor 1001, and the light source 1002 is, for example, axenon light source, an LED light source, an LD light source, or thelike.

[5-2. Example of Application to Internal Information Acquisition SystemIncluding Capsule-Type Endoscope]

The imaging devices of the first and second embodiments according to thepresent technology can be applied to an electronic device for ICG(indocyanine green) (fluorescence imaging method) observation in medicalapplications. In the ICG observation, the excitation light is 760 nm andthe fluorescence is 850 nm, and thus in the case of the imaging deviceof the second embodiment according to the present technology, it is onlyrequired to use one that outputs light having a wavelength of 760 nm isused for the light emitting element.

In the ICG observation, it is desirable that spectral ripples are smalldue to a narrow wavelength band of low sensitivity. The spectral ripplesare generated by interference of a reflection interface, but thespectral ripples can be significantly suppressed in the imaging deviceof the first and second embodiments according to the present technology.Specifically, for example, the ICG wavelength ripples can be minimizedby designing an antireflection film having a film thickness d=wavelengthλ/(4×refractive index n) by using a material having an intermediaterefractive index of a refractive index n=1 to 1.7 of air and thesapphire glass 21 on the outermost surface.

Note that in the case of the imaging device of the second embodimentaccording to the present technology, the antireflection film can beformed simultaneously, which has been conventionally processedseparately for the first substrate and the second substrate and thelight emitting element included in the imaging device of the secondembodiment according to the present technology.

FIG. 11 illustrates a schematic configuration example of an internalinformation acquisition system for patient using a capsule-typeendoscope in a case where the imaging devices of the first and secondembodiments according to the present technology are applied to acapsule-type endoscope.

The internal information acquisition system 3000 includes a capsule-typeendoscope 3100 swallowed by the patient at the time of examination andan external control device 3200 that integrally controls the operationof the internal information acquisition system 3000.

The capsule-type endoscope 3100 has an imaging function and a wirelesscommunication function and, while moving inside an organ such as astomach and an intestine by peristaltic movement or the like until it isnaturally excreted from the patient, sequentially captures images insidethe organ (hereinafter, also referred to as internal images) atpredetermined intervals, and sequentially transmits informationregarding the internal images wirelessly to the external control device3200 outside the body.

The external control device 3200 generates image data for displaying theinternal images on a display device (not illustrated) on the basis ofthe received information regarding the internal images.

In the internal information acquisition system 3000, in this manner, itis possible to obtain an image of the inside of the body of the patientat any time from the time when the capsule-type endoscope 3100 isswallowed until it is excreted.

Configurations and functions of the capsule-type endoscope 3100 and theexternal control device 3200 will be described in detail.

The capsule-type endoscope 3100 is equipped with functions of a lightsource unit 3103, an imaging unit 3105, an image processing unit 3107, awireless communication unit 3109, a power feeding unit 3113, a powersupply unit 3115, a state detection unit 3117, and a control unit 3119in a capsule-type housing 3101.

The light source unit 3103 emits light to an imaging field of view ofthe imaging unit 3105. The imaging unit 3105 receives reflected light oflight with which a body tissue as an observation target is irradiatedand performs photoelectric conversion thereof to generate an electricalsignal corresponding to observation light, that is, an image signalcorresponding to the observation image. The image signal generated bythe imaging unit 3105 is provided to the image processing unit 3107.

The imaging device of the first embodiment according to the presenttechnology is used as the imaging unit 3105, and the imaging device ofthe second embodiment according to the present technology is used as thelight source unit 3103 and the imaging unit 3105.

The image processing unit 3107 includes processors such as a centralprocessing unit (CPU) and a graphics processing unit (GPU), and performsvarious signal processing on the image signal generated by the imagingunit 3105. The signal processing may be minimum processing fortransmitting the image signal to the external control device 3200 (forexample, compression of image data, conversion of frame rate, conversionof data rate and/or conversion of format, and the like). Since the imageprocessing unit 3107 is configured to perform only the minimum necessaryprocessing, the image processing unit 3107 can be achieved in a smallersize and with lower power consumption, and hence is preferable for thecapsule-type endoscope 3100. However, if there is enough space in thehousing 3101 or power consumption margin, the image processing unit 3107may perform further signal processing (for example, noise removalprocessing, other high image quality processing, or the like).

The image processing unit 3107 provides the image signal subjected tothe signal processing to the wireless communication unit 3109 as RAWdata. Note that in a case where information regarding the state(movement, posture, and the like) of the capsule-type endoscope 3100 isacquired by the state detection unit 3117, the wireless communicationunit 3109 may provide the image signal to the wireless communicationunit 3109 by associating with this information. Thus, a position in thebody where an image is captured, an imaging direction of the image, andthe like can be associated with the captured image.

The wireless communication unit 3109 includes a communication devicecapable of transmitting and receiving various information to and fromthe external control device 3200. The communication device includes anantenna 3111 and a processing circuit or the like that performsmodulation processing or the like for transmitting and receivingsignals. The wireless communication unit 3109 performs predeterminedprocessing such as modulation processing on the image signal that hasbeen subjected to the signal processing by the image processing unit3107, and transmits the image signal to the external control device 3200via the antenna 3111. Furthermore, the wireless communication unit 3109receives a control signal related to drive control of the capsule-typeendoscope 3100 from the external control device 3200 via the antenna3111. The wireless communication unit 3109 provides the received controlsignal to the camera head control unit 3119.

The power feeding unit 3113 includes an antenna coil for receivingpower, a power regeneration circuit that regenerates electric power fromthe current generated in the antenna coil, a booster circuit, and thelike. In the power feeding unit 3113, electric power is generated usingwhat is called non-contact charging principle. Specifically, when amagnetic field (electromagnetic wave) having a predetermined frequencyis applied to the antenna coil of the power feeding unit 3113 from theoutside, an induced electromotive force is generated in the antennacoil. The electromagnetic wave may be, for example, a carrier wavetransmitted from the external control device 3200 via an antenna 3201.Electric power is regenerated from the induced electromotive force bythe power regeneration circuit, and the potential thereof isappropriately adjusted in the booster circuit to generate electric powerfor storage. The electric power generated by the power feeding unit 3113is stored in the power supply unit 3115.

The power supply unit 3115 includes a secondary battery and stores theelectric power generated by the power feeding unit 3113. However, inFIG. 11, the illustration of an arrow or the like indicating thedestination of power supply from the power supply unit 3115 is omitted.

The state detection unit 3117 includes sensors, such as an accelerationsensor and/or a gyro sensor, for detecting the state of the capsule-typeendoscope 3100. The state detection unit 3117 can acquire informationregarding the state of the capsule-type endoscope 3100 from detectionresults by the sensors. The state detection unit 3117 provides the imageprocessing unit 3107 with the acquired information regarding the stateof the capsule-type endoscope 3100. In the image processing unit 3107,as described above, information regarding the state of the capsule-typeendoscope 3100 can be associated with the image signal.

The control unit 3119 includes a processor such as a CPU, and integrallycontrols the operation of the capsule-type endoscope 3100 by operatingaccording to a predetermined program. The control unit 3119 implementsthe functions in respective units as described above by appropriatelycontrolling driving of the light source unit 3103, the imaging unit3105, the image processing unit 3107, the wireless communication unit3109, the power feeding unit 3113, the power supply unit 3115, and thestate detection unit 3117 according to a control signal transmitted fromthe external control device 3200.

The external control device 3200 may be a processor such as a CPU orGPU, or a microcomputer or a control board or the like on which aprocessor and a storage element such as a memory are mounted in a mixedmanner. The external control device 3200 has an antenna 3201 and isconfigured to be capable of transmitting and receiving variousinformation to and from the capsule-type endoscope 3100 via the antenna3201.

Specifically, the external control device 3200 controls the operation ofthe capsule-type endoscope 3100 by transmitting a control signal to thecontrol unit 3119 of the capsule-type endoscope 3100. For example, thecontrol signal from the external control device 3200 can changeirradiation conditions of light with respect to the observation targetin the light source unit 3103. Further, the imaging conditions (forexample, the frame rate, the exposure value, and the like in the imagingunit 3105) can be changed by the control signal from the externalcontrol device 3200. Furthermore, the contents of processing in theimage processing unit 3107 and conditions for transmitting the imagesignal by the wireless communication unit 3109 (for example,transmission interval, number of transmitted images, and the like) maybe changed by the control signal from the external control device 3200.

Furthermore, the external control device 3200 performs various imageprocessing on the image signal transmitted from the capsule-typeendoscope 3100, and generates image data for displaying the capturedinternal image on the display device. As the image processing, forexample, various known signal processing such as development processing(demosaic processing), image quality enhancement processing (bandenhancement processing, super-resolution processing, noise reduction(NR) processing, and/or camera shake correction processing, and thelike), and/or enlargement processing (electronic zoom processing) andthe like may be performed. The external control device 3200 controlsdriving of the display device (not illustrated) to display an internalimage captured on the basis of the generated image data. Alternatively,the external control device 3200 may have the generated image datarecorded in a recording device (not illustrated) or printed out by aprinting device (not illustrated).

[5-3. Example of Using Imaging Device]

FIG. 12 is a diagram illustrating an example of using the imagingdevices of the first and second embodiments according to the presenttechnology as an image sensor.

The imaging devices of the first and second embodiments described abovecan be used in various cases of sensing light such as visible light,infrared light, ultraviolet light, and X-ray, as described below, forexample. That is, as illustrated in FIG. 12, for example, the imagingdevice of either one of the first and second embodiments can be used indevices (for example, the electronic device of the third embodimentdescribed above) used in the field of appreciation for taking an imageused for appreciation, the field of traffic, the field of homeappliances, the field of medical or health care, the field of security,the field of beautification, the field of sports, the field ofagriculture, and the like.

Specifically, in the field of appreciation, for example, the imagingdevice of either one of the first and second embodiments can be used indevices for taking images to be used for appreciation, such as digitalcameras, smartphones, and mobile phones with a camera function.

In the field of traffic, for example, the imaging device of either oneof the first and second embodiments can be used in devices for trafficuse, such as an onboard sensor that captures images of the front side,the rear side, the surroundings, the inside, and the like of anautomobile, a monitoring camera that monitors a traveling vehicle and aroad, and a range sensor that measures distance between vehicles forsafe driving such as automatic stop and recognition of a state of adriver.

In the field of home appliances, for example, the imaging device ofeither one of the first and second embodiments can be used in devicesfor home appliances such as a television receiver, a refrigerator, andan air conditioner for capturing a gesture of a user and performing adevice operation in accordance with the gesture.

In the field of medical or health care, for example, the imaging deviceof either one of the first and second embodiments can be used in devicesfor medical or healthcare use, such as an endoscope or a device thatperform angiography by receiving infrared light.

In the field of security, for example, the imaging device of either oneof the first and second embodiments can be used in devices for securityuse such as a surveillance camera for crime prevention or a camera forpersonal identification.

In the field of beautification, for example, the imaging device ofeither one of the first and second embodiments can be used in devicesused for beautification, such as a skin measuring device that capturesan image of the skin, and a microscope that captures an image of thescalp.

In the field of sports, for example, the imaging device of either one ofthe first and second embodiments can be used in devices for sports usesuch as an action camera or a wearable camera for sports use or thelike.

In the field of agriculture, for example, the imaging device accordingto either one of the first and second embodiments can be used in devicesfor agricultural use, such as a camera for monitoring the state of afield or a crop.

[5-4. Example of Application to Endoscopic Surgery System]

The present technology can be applied to various products. For example,the technology according to the present disclosure (the presenttechnology) may be applied to an endoscopic surgery system.

FIG. 13 is a diagram illustrating an example of a schematicconfiguration of an endoscopic surgery system to which the technologyaccording to the present disclosure (the present technology) can beapplied.

FIG. 13 illustrates that an operator (doctor) 11131 performing surgeryon a patient 11132 on a patient bed 11133 using an endoscopic surgerysystem 11000. As illustrated in the diagram, the endoscopic surgerysystem 11000 includes an endoscope 11100, other surgical tools 11110such as a pneumoperitoneum tube 11111 and an energy treatment device11112, a support arm device 11120 that supports the endoscope 11100, anda cart 11200 on which various devices for endoscopic surgery aremounted.

The endoscope 11100 includes a lens barrel 11101 having a region with apredetermined length from a distal end to be inserted into the bodycavity of the patient 11132, and a camera head 11102 connected to a baseend of the lens barrel 11101. In the illustrated example, the endoscope11100 configured as what is called a rigid endoscope having a rigid lensbarrel 11101 is illustrated, but the endoscope 11100 may be configuredas what is called a flexible mirror having a flexible lens barrel.

An opening in which an objective lens is fitted is provided in thedistal end of the lens barrel 11101. A light source device 11203 isconnected to the endoscope 11100, and light generated by the lightsource device 11203 is guided to the distal end of the lens barrel by alight guide extending inside the lens barrel 11101, and is emittedtoward an observation target in the body cavity of the patient 11132through the objective lens. Note that the endoscope 11100 may be aforward-viewing endoscope, an oblique-viewing endoscope, or aside-viewing endoscope.

An optical system and an imaging element are provided inside the camerahead 11102, and reflected light (observation light) from the observationtarget is focused on the imaging element by the optical system. Theobservation light is photoelectrically converted by the imaging element,and an electrical signal corresponding to the observation light, thatis, an image signal corresponding to an observation image is generated.The image signal is transmitted as RAW data to a camera control unit(CCU) 11201.

The CCU 11201 includes a central processing unit (CPU), a graphicsprocessing unit (GPU), and the like, and integrally controls operationsof the endoscope 11100 and the display device 11202. Moreover, the CCU11201 receives an image signal from the camera head 11102 and subjectsthe image signal to various image processing such as developmentprocessing (demosaic processing) for example for displaying an imagebased on the image signal.

By control from the CCU 11201, the display device 11202 displays animage based on the image signal subjected to the image processing by theCCU 11201.

The light source device 11203 includes, for example, a light source suchas a light emitting diode (LED), and supplies the endoscope 11100 withirradiation light at the time of capturing an image of the surgicalsite.

The input device 11204 is an input interface for the endoscopic surgerysystem 11000. The user can input various information and instructions tothe endoscopic surgery system 11000 via the input device 11204. Forexample, the user inputs an instruction to change the imaging conditions(type of irradiation light, magnification, focal length, and the like)by the endoscope 11100.

A treatment tool control device 11205 controls driving of the energytreatment device 11112 for cauterization of tissue, incision, sealing ofblood vessel, or the like. A pneumoperitoneum device 11206 delivers gasinto the body cavity through the pneumoperitoneum tube 11111 in order toinflate the body cavity of the patient 11132 for the purpose of securingthe field of view by the endoscope 11100 and the working space of theoperator. A recorder 11207 is a device capable of recording variousinformation regarding surgery. A printer 11208 is a device capable ofprinting various information regarding surgery in various formats suchas text, image, or graph.

Note that the light source device 11203 that supplies the endoscope11100 with the irradiation light at the time of capturing an image ofthe surgical site can include, for example, a white light source formedby an LED, a laser light source, or a combination thereof. In a casewhere the white light source is formed by a combination of RGB laserlight sources, the output intensity and output timing of each color(each wavelength) can be controlled with high accuracy, and thus whitebalance of a captured image can be adjusted in the light source device11203. Furthermore, in this case, it is possible to irradiate theobservation target with the laser light from each of the RGB laser lightsources in a time-division manner, and control driving of the imagingelement of the camera head 11102 in synchronization with the irradiationtiming, to thereby capture an image corresponding to each of RGB in atime-division manner. According to this method, a color image can beobtained without providing a color filter on the imaging element.

Furthermore, driving of the light source device 11203 may be controlledso as to change the intensity of output light at every predeterminedtime interval. By controlling driving of the imaging element of thecamera head 11102 in synchronization with timing of changing theintensity of the light to acquire images in a time-division manner andsynthesizing the images, images with high dynamic ranges without what iscalled blocked up shadows and blown out highlights can be generated.

Furthermore, the light source device 11203 may be capable of supplyinglight in a predetermined wavelength band corresponding to special lightobservation. In the special light observation, for example, what iscalled narrow band light observation (narrow band imaging) is performedby utilizing the wavelength dependence of light absorption in bodytissue and emitting light in a narrower band as compared withirradiation light in normal observation (that is, white light), tothereby image a predetermined tissue such as blood vessels on a surfacelayer of a mucous membrane with high contrast. Alternatively, in thespecial light observation, fluorescence observation in which an image isobtained by fluorescence generated by emitting excitation light may beperformed. In the fluorescence observation, it is possible to performirradiating a body tissue with excitation light to observe fluorescencefrom the body tissue (autofluorescence observation), or locallyinjecting a reagent such as indocyanine green (ICG) into a body tissueand irradiating the body tissue with excitation light corresponding tothe fluorescence wavelength of the reagent to obtain a fluorescenceimage, or the like. The light source device 11203 may be capable ofsupplying narrowband light and/or excitation light compatible with suchspecial light observation.

FIG. 14 is a block diagram illustrating an example of functionalconfigurations of the camera head 11102 and the CCU 11201 illustrated inFIG. 13.

The camera head 11102 includes a lens unit 11401, an imaging unit 11402,a drive unit 11403, a communication unit 11404, and a camera headcontrol unit 11405. The CCU 11201 has a communication unit 11411, animage processing unit 11412, and a control unit 11413. The camera head11102 and the CCU 11201 are connected in a mutually communicable mannerby a transmission cable 11400.

The lens unit 11401 is an optical system provided at a connectionportion with the lens barrel 11101. The observation light taken in fromthe distal end of the lens barrel 11101 is guided to the camera head11102 and incident on the lens unit 11401. The lens unit 11401 isconfigured by combining a plurality of lenses including a zoom lens anda focus lens.

The imaging unit 11402 is formed by an imaging device (imaging element).The imaging element constituting the imaging unit 11402 may be one (whatis called a single plate type) or multiple (what is called a multi-platetype). In a case where the imaging unit 11402 is formed by a multi-platetype, for example, each imaging element may generate an image signalcorresponding to each of RGB, and a color image may be obtained bysynthesizing them. Alternatively, the imaging unit 11402 may have a pairof imaging elements for acquiring respective image signals for the righteye and the left eye corresponding to 3-dimensional (3D) display.Performing the 3D display enables the operator 11131 to more accuratelygrasp the depth of living tissue at a surgical site. Note that in a casewhere the imaging unit 11402 includes a multi-plate type, multiplesystems of lens units 11401 are provided corresponding to the respectiveimaging elements.

Furthermore, the imaging unit 11402 does not necessarily have to beprovided in the camera head 11102. For example, the imaging unit 11402may be provided inside the lens barrel 11101 immediately after theobjective lens.

The drive unit 11403 includes an actuator, and moves the zoom lens andthe focus lens of the lens unit 11401 by a predetermined distance alongthe optical axis under the control of the camera head control unit11405. Thus, the magnification and focus of the image captured by theimaging unit 11402 can be adjusted as appropriate.

The communication unit 11404 includes a communication device fortransmitting and receiving various information to and from the CCU11201. The communication unit 11404 transmits an image signal obtainedfrom the imaging unit 11402 as RAW data to the CCU 11201 via thetransmission cable 11400.

Furthermore, the communication unit 11404 receives a control signal forcontrolling driving of the camera head 11102 from the CCU 11201 andsupplies the control signal to the camera head control unit 11405. Thecontrol signal includes, for example, information regarding imagingconditions such as information specifying the frame rate of the capturedimage, information specifying the exposure value at the time of imaging,and/or information specifying the magnification and focus of thecaptured image.

Note that the above imaging conditions such as the frame rate, exposurevalue, magnification, and focus described above may be appropriatelyspecified by the user, or may be automatically set by the control unit11413 of the CCU 11201 on the basis of the acquired image signal. In thelatter case, the endoscope 11100 is equipped with what is called an autoexposure (AE) function, an auto focus (AF) function, and an auto whitebalance (AWB) function.

The camera head control unit 11405 controls driving of the camera head11102 on the basis of the control signal from the CCU 11201 received viathe communication unit 11404.

The communication unit 11411 includes a communication device fortransmitting and receiving various information to and from the camerahead 11102. The communication unit 11411 receives an image signaltransmitted from the camera head 11102 via the transmission cable 11400.

Furthermore, the communication unit 11411 transmits to the camera head11102 a control signal for controlling driving of the camera head 11102.Image signals and control signals can be transmitted by electricalcommunication, optical communication, or the like.

The image processing unit 11412 subjects the image signal that is RAWdata transmitted from the camera head 11102 to various image processing.

The control unit 11413 performs various control related to imaging ofthe surgical site or the like by the endoscope 11100 and display of acaptured image obtained by the imaging of the surgical site or the like.For example, the control unit 11413 generates a control signal forcontrolling driving of the camera head 11102.

Furthermore, the control unit 11413 causes the display device 11202 todisplay the captured image of the surgical site or the like on the basisof the image signal subjected to the image processing by the imageprocessing unit 11412. At this time, the control unit 11413 mayrecognize various objects in the captured image using various imagerecognition techniques. For example, the control unit 11413 can detectthe shapes of edges, colors, and the like of an object included in thecaptured image, to thereby recognize a surgical tool such as forceps, aspecific biological part, bleeding, mist when using the energy treatmentdevice 11112, or the like. When causing the display device 11202 todisplay the captured image, the control unit 11413 may use a recognitionresult thereof to superimpose various surgical support information onthe image of the surgical site. By the surgical support informationsuperimposed and presenting to the operator 11131, the burden on theoperator 11131 can be reduced and the operator 11131 can surely proceedwith the surgery.

The transmission cable 11400 that connects the camera head 11102 and theCCU 11201 is an electrical signal cable compatible with electricalsignal communication, an optical fiber compatible with opticalcommunication, or a composite cable thereof.

Here, although the communication is performed by wire using thetransmission cable 11400 in the illustrated example, the communicationbetween the camera head 11102 and the CCU 11201 may be performedwirelessly.

The example of the endoscopic surgery system to which the technologyaccording to the present disclosure can be applied has been describedabove. The technology according to the present disclosure can be appliedto the endoscope 11100, (the imaging unit 11402 of) the camera head11102, and the like among the configurations described above.Specifically, the solid-state imaging device 111 of the presentdisclosure can be applied to the imaging unit 10402. By applying thetechnology according to the present disclosure to the endoscope 11100,(the imaging unit 11402 of) the camera head 11102, and the like, it ispossible to improve yield and reduce cost related to manufacturing.

Here, the endoscopic surgery system has been described as an example,but the technology according to the present disclosure may be applied toother, for example, microscopic surgery systems and the like.

Note that the present technology is not limited to the above-describedembodiments and application examples, and various modifications arepossible without departing from the gist of the present technology.

Furthermore, the effects described in the present description are merelyexamples and are not limited, and other effects may be provided.

Furthermore, the present technology can also employ the followingconfigurations.

[1]

An imaging device including:

a first substrate including a first pixel array unit in which aplurality of pixels having at least a first photoelectric conversionunit that performs photoelectric conversion is arranged in atwo-dimensional manner, a first wiring layer, and a first support layerstacked in this order; and

a second substrate including a second pixel array unit in which aplurality of pixels having at least a second photoelectric conversionunit that performs photoelectric conversion is arranged in atwo-dimensional manner, a second wiring layer, and a second supportlayer stacked in this order,

in which the first support layer and the second support layer are bondedto each other to form a stacked structure of the first substrate and thesecond substrate, and

at least one of the first support layer or the second support layerincludes an antireflection layer.

[2]

The imaging device according to [1], in which the antireflection layerincludes a light-shielding film that shields excitation light with whicha subject is irradiated and/or a transmission film that transmitsfluorescence emitted from the subject by the excitation light.

[3]

The imaging device according to [2], in which the excitation light has awavelength of 760 nm±10 nm, and the fluorescence has a wavelength of 850nm±10 nm.

[4]

The imaging device according to [1], in which the first support layerincludes a first antireflection layer, and the second support layerincludes a second antireflection layer.

[5]

The imaging device according to [4], in which

the first antireflection layer includes a light-shielding film thatshields excitation light with which a subject is irradiated and/or atransmission film that transmits fluorescence emitted from the subjectby the excitation light, and

the second antireflection layer includes a light-shielding film thatshields excitation light with which a subject is irradiated and/or atransmission film that transmits fluorescence emitted from the subjectby the excitation light.

[6]

The imaging device according to [5], in which the excitation light has awavelength of 760 nm±10 nm, and the fluorescence has a wavelength of 850nm±10 nm.

[7]

The imaging device according to [1], in which the first support layerincludes a first adhesive layer, a first antireflection layer, and asecond adhesive layer stacked in this order, and the second adhesivelayer and the second support layer are bonded to each other to form astacked structure of the first substrate and the second substrate.

[8]

The imaging device according to [7], in which the first antireflectionlayer includes a light-shielding film that shields excitation light withwhich a subject is irradiated and/or a transmission film that transmitsfluorescence emitted from the subject by the excitation light.

[9]

The imaging device according to [8], in which the excitation light has awavelength of 760 nm±10 nm, and the fluorescence has a wavelength of 850nm±10 nm.

[10]

The imaging device according to any one of [7] to [9], in which thefirst adhesive layer includes a silicon oxide film, the firstantireflection layer includes a silicon nitride film, and the secondadhesive layer includes a silicon oxide film.

[11]

The imaging device according to any one of [7] to [9], in which thefirst adhesive layer includes a silicon nitride film, the firstantireflection layer includes a silicon oxide film, and the secondadhesive layer includes a silicon nitride film.

[12]

The imaging device according to [1], in which the second support layerincludes a third adhesive layer, a second antireflection layer, and afourth adhesive layer stacked in this order, and the third adhesivelayer and the first support layer are bonded to each other to form astacked structure of the first substrate and the second substrate.

[13]

The imaging device according to [12], in which the second antireflectionlayer includes a light-shielding film that shields excitation light withwhich a subject is irradiated and/or a transmission film that transmitsfluorescence emitted from the subject by the excitation light.

[14]

The imaging device according to [13], in which the excitation light hasa wavelength of 760 nm±10 nm, and the fluorescence has a wavelength of850 nm±10 nm.

[15]

The imaging device according to any one of [12] to [14], in which thethird adhesive layer includes a silicon oxide film, the secondantireflection layer includes a silicon nitride film, and the fourthadhesive layer includes a silicon oxide film.

[16]

The imaging device according to any one of [12] to [14], in which thethird adhesive layer includes a silicon nitride film, the secondantireflection layer includes a silicon oxide film, and the fourthadhesive layer includes a silicon nitride film.

[17]

The imaging device according to [1], in which

the first support layer includes a first adhesive layer, a firstantireflection layer, and a second adhesive layer stacked in this order,

the second support layer includes a third adhesive layer, a secondantireflection layer, and a fourth adhesive layer stacked in this order,and

the second adhesive layer and the third adhesive layer are bonded toeach other to form a stacked structure of the first substrate and thesecond substrate.

[18]

The imaging device according to [17], in which

the first antireflection layer includes a light-shielding film thatshields excitation light with which a subject is irradiated and/or atransmission film that transmits fluorescence emitted from the subjectby the excitation light, and

the second antireflection layer includes a light-shielding film thatshields excitation light with which a subject is irradiated and/or atransmission film that transmits fluorescence emitted from the subjectby the excitation light.

[19]

The imaging device according to [18], in which the excitation light hasa wavelength of 760 nm±10 nm, and the fluorescence has a wavelength of850 nm±10 nm.

[20]

The imaging device according to any one of [17] to [19], in which

the first adhesive layer includes a silicon oxide film, the firstantireflection layer includes a silicon nitride film, and the secondadhesive layer includes a silicon oxide film, and

the third adhesive layer includes a silicon nitride film, the secondantireflection layer includes a silicon oxide film, and the fourthadhesive layer includes a silicon nitride film.

[21]

The imaging device according to any one of [17] to [19], in which

the first adhesive layer includes a silicon nitride film, the firstantireflection layer includes a silicon oxide film, and the secondadhesive layer includes a silicon nitride film, and

the third adhesive layer includes a silicon oxide film, the secondantireflection layer includes a silicon nitride film, and the fourthadhesive layer includes a silicon oxide film.

[22]

The imaging device according to any one of [1] to [21], furtherincluding a light emitting element that outputs excitation light withwhich a subject is irradiated.

[23]

The imaging device according to any one of [1] to [22], in which thesecond wiring layer has a wiring, and the wiring is a transparentwiring.

[24]

The imaging device according to any one of [1] to [23], in which thesecond wiring layer has a wiring, and the wiring is arranged in at leastone area corresponding to between the pixels adjacent to each other inthe plurality of pixels arranged two-dimensionally in the second pixelarray unit.

[25]

The imaging device according to any one of [1] to [24], in which thesecond wiring layer has a wiring, and the wiring is arranged only in anarea corresponding to the pixels of at least a part of the plurality ofpixels arranged two-dimensionally in the second pixel array unit.

[26]

An electronic device equipped with the imaging device according to anyone of [1] to [25].

REFERENCE SIGNS LIST

-   1 (1-1, 1-2, 1-6, 1-8) Imaging device-   31 (31A, 31B), 32 (32A, 32B) Adhesive layer-   41, 42 Antireflection layer-   101 First substrate-   101A First support layer-   101B First wiring layer-   101C First pixel array unit-   102 Second substrate-   102A Second support layer-   102B Second wiring layer-   102C Second pixel array unit

What is claimed is:
 1. An imaging device comprising: a first substrateincluding a first pixel array unit in which a plurality of pixels havingat least a first photoelectric conversion unit that performsphotoelectric conversion is arranged in a two-dimensional manner, afirst wiring layer, and a first support layer stacked in this order; anda second substrate including a second pixel array unit in which aplurality of pixels having at least a second photoelectric conversionunit that performs photoelectric conversion is arranged in atwo-dimensional manner, a second wiring layer, and a second supportlayer stacked in this order, wherein the first support layer and thesecond support layer are bonded to each other to form a stackedstructure of the first substrate and the second substrate, and at leastone of the first support layer or the second support layer includes anantireflection layer.
 2. The imaging device according to claim 1,wherein the antireflection layer includes a light-shielding film thatshields excitation light with which a subject is irradiated and/or atransmission film that transmits fluorescence emitted from the subjectby the excitation light.
 3. The imaging device according to claim 2,wherein the excitation light has a wavelength of 760 nanometers±10nanometers, and the fluorescence has a wavelength of 850 nanometers±10nanometers.
 4. The imaging device according to claim 1, wherein thefirst support layer includes a first antireflection layer, and thesecond support layer includes a second antireflection layer.
 5. Theimaging device according to claim 4, wherein the first antireflectionlayer includes a light-shielding film that shields excitation light withwhich a subject is irradiated and/or a transmission film that transmitsfluorescence emitted from the subject by the excitation light, and thesecond antireflection layer includes a light-shielding film that shieldsexcitation light with which a subject is irradiated and/or atransmission film that transmits fluorescence emitted from the subjectby the excitation light.
 6. The imaging device according to claim 5,wherein the excitation light has a wavelength of 760 nanometers±10nanometers, and the fluorescence has a wavelength of 850 nanometers±10nanometers.
 7. The imaging device according to claim 1, wherein thefirst support layer includes a first adhesive layer, a firstantireflection layer, and a second adhesive layer stacked in this order,the second support layer includes a third adhesive layer, a secondantireflection layer, and a fourth adhesive layer stacked in this order,and the second adhesive layer and the third adhesive layer are bonded toeach other to form a stacked structure of the first substrate and thesecond substrate.
 8. The imaging device according to claim 7, whereinthe first antireflection layer includes a light-shielding film thatshields excitation light with which a subject is irradiated and/or atransmission film that transmits fluorescence emitted from the subjectby the excitation light, and the second antireflection layer includes alight-shielding film that shields excitation light with which a subjectis irradiated and/or a transmission film that transmits fluorescenceemitted from the subject by the excitation light.
 9. The imaging deviceaccording to claim 8, wherein the excitation light has a wavelength of760 nanometers±10 nanometers, and the fluorescence has a wavelength of850 nanometers±10 nanometers.
 10. The imaging device according to claim7, wherein the first adhesive layer includes a silicon oxide film, thefirst antireflection layer includes a silicon nitride film, and thesecond adhesive layer includes a silicon oxide film, and the thirdadhesive layer includes a silicon nitride film, the secondantireflection layer includes a silicon oxide film, and the fourthadhesive layer includes a silicon nitride film.
 11. The imaging deviceaccording to claim 7, wherein the first adhesive layer includes asilicon nitride film, the first antireflection layer includes a siliconoxide film, and the second adhesive layer includes a silicon nitridefilm, and the third adhesive layer includes a silicon oxide film, thesecond antireflection layer includes a silicon nitride film, and thefourth adhesive layer includes a silicon oxide film.
 12. The imagingdevice according to claim 1, further comprising a light emitting elementthat outputs excitation light with which a subject is irradiated. 13.The imaging device according to claim 1, wherein the second wiring layerhas a wiring, and the wiring is a transparent wiring.
 14. The imagingdevice according to claim 1, wherein the second wiring layer has awiring, and the wiring is arranged in at least one area corresponding tobetween the pixels adjacent to each other in the plurality of pixelsarranged two-dimensionally in the second pixel array unit.
 15. Theimaging device according to claim 1, wherein the second wiring layer hasa wiring, and the wiring is arranged only in an area corresponding tothe pixels of at least a part of the plurality of pixels arrangedtwo-dimensionally in the second pixel array unit.
 16. An electronicdevice equipped with the imaging device according to claim 1.